the study of the relationship between physical stimuli and psychological response

measures sound by pitch loudness and localization

pitch

describes how high or low a sound is perceived. In general is rises as Hz rises

loudness

subjective experience associated with sound pressure (amplitude)

equal loudness contours

in order for a sound to be perceived as louder you need to increase the intensity. In order for people to perceive different freq as the same established anchor or reference tone you need to increase the intensity. more for lower freq